While ERPs have proved invaluable in delineating the timing and amount of specific aspects of information processing in cooperative and cognitivity intact subjects, they have been less helpful in the assessment of patients unable or unwilling to cooperate with testing procedures. We have already demonstrated that certain cognitive ERP components (P300 and Mismatch Negativity (MMN)) can be elicited automatically, in young healthy controls, and explored some parameters for optimizing their appearance. We propose to continue developing paradigms for eliciting cognitive event-related potential (ERP) components automatically, and will apply these paradigms along with conventional task-related paradigms to assess cognitive changes associated with aging and dementia. Specifically, we will (1) employ auditory stimuli to explore ways of automatically eliciting N400, a component usually elicited visually by semantically incongruous words; (2) test for the best auditory stimulus frequency and stimulus duration characteristics for eliciting the automatic P300 in healthy elderly; (3) test healthy young and old subjects on both automatic and effortal versions of the P300 and MMN paradigms, as well as the auditory N400 paradigm to assess cognitive changes associated with normal aging; and (4) test Alzheimer's patients on the same paradigms to determine whether effortfully or automatically elicited ERP components, or some combination of them best delineate cognitive deficits in the patient group.